This research proposal is designed to enable continued participation in the Primary Breast and Colorectal Therapy Group-NSABP. The overall specific aims of the NSABP are to improve disease-free survival in patients with primary operable breast and colorectal cancers. (See the NSABP Headquarters Grant Application for protocol rationale and overall scientific achievements to-date). The University of Cincinnati has been an NSABP member since June 1987 and is currently following 175 patients previously randomized on long term adjuvant protocols. Since joining the NSABP we have had a continued increase in accrual from each of our component sites, bringing the total to 62 patients for the period February 1, 1990 through January 31, 1991. A core component of the University of Cincinnati Program has been the increasing participation of community-based oncologists as a supplement to medical center-based accruals. The University of Cincinnati's participation in the NSABP has been characterized by high quality patient follow-up and data management with a delinquency rate of three percent. Our NSABP evaluation score for breast protocols placed the University of Cincinnati, third among 159 subcontracts, and fourth among 157 subcontracts for colorectal protocols. For 1988, 1989, 1990 the University of Cincinnati program was awarded the NSABP Exemplary Performance Award. Recently efforts to involve community physicians have intensified through the award of a Cooperative Group Outreach Program Grant from the NSABP. With continued expansion of our center-based accrual and increased community outreach, we expect to place 95 patients per year on NSABP protocols during the first 12 month budget period of the current application. The entry of these patients into NSABP protocols will enable a more rapid and effective evaluation of current therapeutic regimens and will provide information for the design of future studies.